The present invention relates to shotguns in general and to bullpup shotguns incorporating a revolver style cylinder containing multiple shotgun rounds.
Many of the features of a shotgun which make it useful for relatively short-range hunting, also makes it useful for short-range defense or offense, particularly when a relatively short barrel is used. A shotgun by its nature is a relatively short-range weapon in comparison to a rifle. Shotguns have relatively low chamber pressures and muzzle velocities—typically a third to one half that of a rifle, and often have a smooth bore rather than rifled barrels. Shotguns are relatively short-range devices with a maximum range of only 700-2,000 feet for shot loads, and an effective range for self-defense of perhaps 50 feet. Using a short barrel on a shotgun has relatively little effect on this effective range. Shotguns also can employ a wide variety of ammunition with generally relatively large total projectile mass of varying area effect. By selecting the proper ammunition, immediate knockdown can be achieved with relatively little penetration of structures, thereby preventing collateral damage. The rifle, on the other hand is effective, at long ranges being accurate and effective at ranges of between 300 and over 1,000 yards. Rifle use in close combat or defense, especially in urban settings, may result in unintended casualties, as a rifle round will typically travel through multiple structures before coming to rest. For many military and police actions both the rifle and the shotgun offer advantages, and when arming for a particular mission or situation at times it will not be clear whether a shotgun or rifle will be most effective. In some situations it may even be such that both capabilities will be needed nearly simultaneously, and yet generally carrying both weapons and being able to use them simultaneously is impractical.
Shotguns have been developed which mount under the barrel of a rifle providing the advantage of having both guns incorporated into a single weapon.
Advantageously a shotgun for mounting under a rifle barrel should be lightweight, with the center of gravity positioned as rearwardly as possible, it should provide for multiple shots, be readily loaded with different types of ammunition, and have an action which is not dependent on gas pressure or recoil effect.